Certain known guidance methods rely on associating two techniques:                creating a geographical map or plan; and        locating the user geographically.One such method is thus implemented in the satellite guidance system known as the Global Positioning System (GPS).        
The drawbacks of the above-mentioned techniques are as follows:                mapping a complex area such as the inside of a building is difficult to perform; and        locating a user in complex surroundings such as a city block or inside a building is complicated to perform, in particular because of multiple reflections and because of shadow effects affecting the electromagnetic waves used for such locating.        
On the basis of US patent application 2002/119791, there is also known a method of guiding a user (such as a pedestrian or a motorist) towards a preselected destination. To do this, a management network (known as an “LFN network”) uses this preselection (known as a target code) to determine a series of fixed radio transmitters (known as local fixed signal sites or LFS) from a set of such transmitters, in such a manner that the user moves from transmitter to transmitter all the way to the destination. The user goes towards each successive transmitter while consulting a radio receiver (referred to as a tracking unit) that acts in known manner to inform the user about the direction to follow.
Thus, in that known method, each user path is marked by a series of transmitters acting as beacons. Given the above-mentioned complexity of the surroundings in question, those transmitters need to be close to one another so that the distance between the user and each successive transmitter is small; furthermore, it is necessary to provide a sufficient number of transmitters to be able to set up different paths as a function of different destinations. That method thus has the drawback of requiring a very dense set of fixed transmitters to be installed, which transmitters are connected to as a network.